1. Field of the Invention
The present invention is generally concerned with clutch cover assemblies, that is to say the assembly of parts which, in order to make up a clutch, in particular for an automotive vehicle, is fastened as a unit to a reaction plate or flywheel with a friction disk disposed between them.
2. Description of the Prior Art
As is known, a clutch cover assembly generally comprises a first generally annular member called the cover through which it is adapted to be attached to the associated reaction plate, a second generally annular member called the pressure plate which is constrained to rotate with said cover whilst being mounted so as to be movable axially relative to the latter, and which is adapted to clamp the friction disk axially against the reaction plate, and elastic means which, for the purposes of this clamping or engagement, urge said pressure plate in the direction towards said reaction plate, said elastic means bearing for this purpose on the cover so as to exert a force in the axial direction on the pressure plate.
Elastic means of this kind may, for example, form part of a third generally annular member called the diaphragm spring which is inserted axially between the pressure plate and the cover and comprises, on the one hand, a circumferentially continuous peripheral part forming a Belleville washer and constituting said elastic means and, on the other hand, a central part divided into radial fingers by slots, said central part forming levers by means of which the assembly may be operated to disengage it.
Generally speaking, a diaphragm spring of this kind usually bears directly on the pressure plate having for this purpose an annular bead projecting in the axial direction, possibly circumferentially subdivided into separate bosses.
It has been proposed to have the diaphragm spring bear on the pressure plate through the intermediary of a fastened on member, referred to for convenience as the "bearing" member. A member of this kind is described in U.S. patent application Ser. No. 601,251 filed Apr. 17, 1984, now U.S. Pat. No. 4,529,074. In this application the bearing member has a two-fold function. Its first function is to close off cooling channels which the pressure plate features. Its second function is to provide an annular bead for the diaphragm spring to bear on in order to apply force to the pressure plate.
An objective of the present invention is to confer a further function on the bearing member on the pressure plate, and possibly to reduce its assembly time and consequently to reduce the manufacturing cost of clutch cover assemblies equipped with a bearing member of this kind.